Pulsator



July 3, 1951 5 J, ERLING 2,559,244

PULSATOR Filed May 5, 1945 Patented July 3, 1951 UNITED STATES ZTENT OFFICE.

PULSATOR a corporation of Sweden Application May 5, 1945, Serial No. 592,255 In Sweden May 23, 1944 9 Claims. l

The frequency of pulsations in a pulsator is regulated by means of an adjustable throttle device, comprising anopening through which the aircurrent has to pass and in the opening a part having a conical end, susceptible of being axially moved and thereby more or less throttling the opening. The position of the part is lcontrolled by a screw, enabling its conical portion to be moved into or out of the opening. The device is thus similar to a needle valve, Instead of being screwed, the needle may also be arranged to be pushed into and through the opening which is then filled up completely. rhis has the advantage that dust particles and the like accumulating in the space between the point of the needle and the edges of the opening during operation are removed, the original throughflow area thereby being restored.

Experience has shown that the operator of milking machines often adjusts the pulsator to work to too high a frequency, the throughflow capacity of the machine thereby being unfavourably influenced. According te my invention this inconvenience is avoided or reduced by providing a non-regulatable throttle in series with the regulatable throttle. When the regulatable throttle is adjusted to give too large athroughow area, so that the frequency would become too high, the effect of the extra throttle will be to limit the pulsation r-ate. The pulsator is still regulatable, but there is an upper limit to the frequency determined by the fixed throttle, which may preferably be a circular opening in a part located in the path of the air current.

The combination of a regulatable throttle in the form of a needle valve and a throttle coupled in series therewith and being a circular opening which determines the degree of throttling has another considerable advantage due to the following circumstances, The needle valve comprises a circular opening, the greater part of which is filled by the conical portion of the needle during operation. The throttled space is therefor annular in shape and forms a comparatively very narrow slit between the needle and the edge of the opening. In fact, the width of the slit is so small that a great deal of the dust particles of the air stick therein, and the valve consequently acts as a filter. This is very important with regard to the fixed throttle having the form of a circular opening and arranged in series with the needle valve, because particles of a size which would stick in and clog the opening cannot then penetrate to the iixed throttle. The slit formed by the needle and its seat thus acts as a filter and (Cl. 13S-45) 2 protects the non-regulatable throttle against clogging.

If the slit is clogged to such a degree that the frequency of pulsations is substantially reduced, the right frequency may easily be re-established by adjusting the valve or momentarily pushing the needle through the opening.

The accompanying drawing shows by way of example some embodiments of the invention. In the drawing, Fig. 1 is a sectional View of one form of the new throttling arrangement; Fig. 2 is a detail sectional view of part of the arrangement shown in Fig. l; Fig. 3 is a sectional view of part of a modied form of the throttling arrangement; Fig. ll is a detail sectional view of part of the Fig. 3 construction, and Fig. 5 is a sectional view of part of still another form of the invention.

Into the housing of the pulsator l is threaded a sleeve 2, in which a spindle 3 of a needle valve is guided. The spindle 3 carries a needle l and is also provided with a shoulder 5 for a spring 6, arranged to keep the needle 4 in the position illustrated on the drawing. Against the action of the spring 6 the needle ll may however be pushed by hand through an opening in a seat l. The needle is thus arranged to co-operate with the opening to form a throttle. The point of the needle is conical and therefore the size of the throughflow area of the valve depends on the axial position of the needle. The position may be changed by adjusting the sle-eve 2 in the pulsator housing. Between the seat l and the needle ll an annular slit is thereby obtained, the width of which corresponds to a given frequency of pulsations. If required, the dust may be removed from the slit by momentarily pushing the needle l through the opening in seat l.

The seat 'l is provided by a part 8 having a bore into which a sleeve 9 is screwed, the side of the latter being provided with a small bore ll] which, as illustrated, has a smaller through-flow area than the adjustable throttle @ll-1 when the latter is fully opened. This hole It is the nonregulatable throttle coupled in series with the needle valve, The air current to be throttled is passed through an enclosed space, formed by a channel il, communicating with a chamber I2 in which the spring and the needle valve 4, 'i are located, and through the hollow parts 8 and Q and the channels i3 and lll.

In order to prevent the sleeve 2 from being screwed out so far that the needle i leaves the opening of the seat 1, in which case the filter eiiect of the valve would disappear, a device for limiting the outward movement of the needle 3 should be provid-ed. According to Fig. 1 the part 8 is therefore provided with an upwardly projecting sleeve I5, embracing the needle and provided with a transverse opening I6 forming a stop for a pin I'I on the spindle 3. When the needle has been raised so much that the pin I1 has reached the upper surface of the opening I6, the movement of the needle stops in this position and the needle no longer follows the sleeve 2 when this is screwed-up. In order to prevent leakage between the part 8 and the housing of the pulsator at the packing I8,` the. elasticity of the spring 6 should be sufficiently great to enable it to keep the part 8 in contact with the packing I8 as long as the thread of the sleeve 2 engages with the corresponding thread of the pulsator housing. The housing may advantageously be pro'- vided with a recess I9, so that the threads no longer engage the one with the other when the upper limit of the range of regulation of the needle valve has been passed. The channel I I then enters into direct communica-tion through the top of housing I with the atmosphere surrounding the pulsator, thereby stopping the pulsator operation. By this means one obtains full safety that, during operation, the point of the needle 4 will always form a sufficiently narrow slit with the seat 'I to ensure lter effect.

Figs. 3 and 4 show another embodiment for ensuring lter effect. In this case the object is to limit, during operation, the movability of the sleeve 2 in such a degree that the co-operation between the point of the needle and the seat is ensured. The sleeve 2 is provided with a shoulder 20 which contacts with a slit-up metal ring 2| located in an annular groove 22 in the pulsator housing, when the sleeve 2 is screwed up. As shown in Fig. 4, the construction of the sleeve 2 is such as to enable the ring 2| to be put into place and removed after the sleeve has been i screwed down to contact with a shoulder in the pulsator housing. For this purpose the ring 2! should be suiciently elastic to be inserted into and taken out of the groove.

The lter effect may also be ensured as indicated in Fig. 5. Below its conical portion the needle 4 is provided with a cylindric portion 23, making it sure that there is always a suiiiciently narrow slit between the needle G and the edge of the opening to constantly ensure iilter effect during operation. The portion 23 may preferably be of the same length as or somewhat longer than the maximum length of engagement between the sleeve 2 and the pulsator housing.

It was assumed above that the air passing through the throttles comes from the atmosphere and rst passes through one or more of the pulsation chambers of the pulsator. This air consequently contains impurities. It has, however, also been endeavoured to regulate the frequency by means of a quantity of air, hermetically separated from the atmosphere, and reciprocating through the throttle. lates to pulsators operating in this manner. It will be understood that any gas or liquid may be used instead of air.

I claim:

1. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a uid passage adapted to communicate at its ends with different parts of the pulsator, two throttles disposed in series in said passage, one of the throttles including a needle valve and a coacting seat member which are relatively adjustable, and manual means for relatively adjusting the needle valve and sont The invention also remember, the other throttle including a hollow screw plug threaded into the seat member and having a small opening of constant restriction providing a through-flow area restricted to limit the frequency of pulsations to a practically usable value regardless of said manual adjustment.

2. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a fluid passage adapted to communicate at its ends with diierent parts of the pulsator, two throttles disposed in series in said passage, one of the throttles including a needle valve and a coacting seat member which are relatively adjustable, and manual means for relatively adjusting the needle valve and seat member, the other throttle having a throughflow area restricted to limit the frequency of pulsations to a practically usable value regard- Vless Vof said manual adjustment, and means for limiting adjustment of the needle valve away from its seat to a distance such that the needle surface is. always so close to the wall of the seat opening that dust particles cannot penetrate to the other throttle.

3. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a iiuid passage adapted to communicate at its ends with diierent parts of the pulsator, two throttles disposed in series in said passage, one of the throttles including a needle valve and a coacting seat member which are relatively adjustable, and manual means for relatively adjusting the needle valve and seat member, a sleeve extending from the valve seat and having a lateral opening, and a pin on the needle valve slidable in the sleeve opening, one end or" the sleeve forming a stop for the pin to .limit adjustment of the needle valve away from its seat to a distance such that the needle surface is always so close to the wall of the seat opening that dust particles cannot penetrate to the other throttle, said other throttle having a through-now area restricted to limit the frequency of pulsations to a practically usable value regardless of said manual adjustment.

4. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a iiuid passage adapted to communicate at its ends with diierent parts of the pulsator, two throttles disposed in series in said passage, Yone of the throttles including a needle valve, means for manually adjusting said last throttle including an adjustable sleeve for guiding and adjusting the needle valve, the

housing having a groove adjacent the sleeve, and an elastic ring in the groove forming a stop for limiting adjustment of the sleeve, the other throttle having a through-flow area restricted to limit the frequency of pulsations to a practically usable value regardless of said manual adjustment.

5. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a fluid passage adapted to communicate at its ends with diierent parts of the pulsator, two throttles disposed in series inV said passage, means for manually adjusting at least one of the throttles, the other throttle having a through-now area restricted to limit the frequency of pulsations toY a practically usable value regardless of said manual adjustment, the manually adjustable throttle including a valve member and a coacting seat having a valve opening, the valve member having a portion which adjustment of the valve member toward the seat decreases the through-flow area of the valve opening, and a cylindrical portion extending through the valve opening from the smaller end of said tapered portion and of a length such that the cylindrical portion remains in the valve opening upon maximum adjustment of the valve member away from the seat, whereby the cylindrical portion insures a constant ltring effect to prevent dust particles from penetrating to the other throttle.

6. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a fluid passage adapted to communicate at its ends with different parts of the pulsator, two throttles disposed in series in said passage, means for manually adjusting at least one of the throttles, the other throttle having a through-flow area restricted to limit the frequency of pulsations to a practically usable value regardless of said manual adjustment, said other throttle being xed, the manually adjustable throttle having an annular passage of variable through-now area, and means for limiting adjustment of the adjustable throttle whereby said variable through-110W area is maintained suiciently narrow so that dust particles cannot penetrate to the xed throttle.

7. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing lhaving a fluid passage adapted to communicate at its ends with different parts of the pulsator, two throttles disposed in series in said passage, means for manually adjusting at least one of the throttles, the other throttle quency of pulsations of a pulsator, which comprises a housing having a fluid passage adapted to communicate at its ends with different parts of the pulsator, two throttles disposed in series in said passage, means for manually adjusting at least one of the throttles, the other throttle having a through-flow area restricted to limit the frequency of pulsations to a practically usable value regardless of said manual adjustment, and partitions hermetically sealing from the atmosphere the luid flowing in said passage.

9. An arrangement for determining the frequency of pulsations of a pulsator, which comprises a housing having a uid passage adapted to communicate at its ends with different parts of the pulsator, two throttles disposed in series in said passage, one of the throttles being a member having a fixed circular through-110W opening, the other throttle including a needle valve and a coacting seat member dening an annular through-flow opening, manual means for relatively adjusting the needle valve and seat member to vary the through-flow area of said annular opening, the xed opening acting to limit the pulsation frequency when said annular opening becomes larger in through-flow area than the fixed opening, and means for limiting adjustment of said manual means to maintain the width of said annular opening less th-an the width of said fixed opening, whereby the annular opening acts as a filter to prevent clogging of the fixed opening.

SVEN JOHAN ERLING.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 726,395 Bedworth et al Apr. 28, 19"()3 1,217,899 Barrus Mar. 6, 1917 1,679,219 Hunc July 31, 1928 2,043,428 Cullen June 9, 1936 2,104,853 Daubenmeyer Jan. 11, 1938 2,367,106 Dolch 1 Jan. 9, 1945 2,420,544 Jones May 13, 1947 

